Control for electrical systems.



C. F. KETTERING.

CONTROL FoR ELECTRICAL SYSTEMS.

APPLICATION FILED NOV. Il. i912.

Patented .T1115r 17', 1917.

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C. F. KETTERING. CONTROL FOR ELECTRICAL SYSTEMS.

APFLCATION FILED NOV. Il. 15H2'A UNITED STATES y inrTENT OFFICE;

CHARLES F. KETTERING, F DAYTON, OHIO, ASSIGN OR T0 THE DAYTON ENGINEERING LABORATORIES CO., A CORPORATION OF OHIO.

CONTROL FOR ELECTRICAL SYSTEMS.

Specification o f Letters Patent.

Patented July 17, 1917.

Application led November 11, 1912. Serial No. 730,733.

To allwhom it may concern.'

Be it known that I, CHARLES F. Kmnn- INo, a citizen of the United States, residing at Dayton, county of Montgomery, and State of Ohio, have invented certain new and useful Improvements in Controls 'for Electrical Systems, of which the following is a full, clear, and exact description.

This invention relates to an improvement in regulators vfor electrical systems and more particularly to regulatorsof that t pe which` are adapted to control certain e ectrical conditions, by varying the resistance in relation thereto. y

The present invention is particularly adapted for electrical systems, wherein an electrical machine is employed for supplying current, either directly to work circuits or to an accumulator, from which current mav be drawn, for any suitable purpose.

ne of the objects of the present invention is to provide means of regulation,

which, when combined with a system embodying a current generator, employed for furnishing power directly to. Work circuits, will maintain the voltage of the out-put of the machine, and also the voltage of the work circuits, substantially constant.

In certain instances it may be desirable to have the means of regulation controlled by certain functions of the electric machine which is to be controlled.

More specifically, in one of the preferred embodiments of the present invention which is disclosed in the present application, simply for the purposes of illustration, the volt- A age of the electric machine tends to control certain instrumentalities which in turn will act upon the electric machine itself, and tend to prevent the voltage across the terminals of the machine from increasing above a certain determined maximum, regardless of the speed of the machine.

Again, when, the regulator is combined with systems, wherein a current generator and an accumulator are in combination, the efi'cct of the machine, relative to the regulator, will, under certain circumstances, effect the control of the voltage of its output, through thc action of the regulator, while under other circumstances, the condition of the accumulator will so affect the regulator 4that the electric machine will be maintained in proper condition.

Another object of the present invention is to provide a re ulator having a movable element, buoyantly supported within a container, but having no permanent or positive connection therewith, which is automatically actuated to vary the resistance, relative to a given electrical condition or circuit.

Another object of the present invention is to provide a regulator, having a movable element, so combined with its associated parts and control mechanism, that the frictional resistance thereof, in its movement from one position to another, will be reduced toa minimum.

Further objects and advantages of the present invention will be clearly ap arent from the following description, re erence being had to the accompanying drawings, wherein preferred forms of the present 1nvention are clearly illustrated.

Figure 1 is a diagrammatic view, showing one electrical system of generation and distribution, wherein a regulator of the present type may be employed to great advantage.

Figs. 2 and 3 are views in side and front the regulator and its associated mechanical parts, embodied in the present invention; portions of Fig. 3 being shown in section for the sake of clearness.

Fig. 4 is a vertical sectional view of the regulator or container. tube and its associated parts.

Figs. 5 and G are detail views of the movable or plungerl clement of the regulator.

Figs. 7 and S are sectional views of modified forms of the regulator tube and its associated parts.

Referring to the drawings, it will be observed that the diagrammatic view in Fig. 1, discloses a system, wherein a dynamo or generator of the shunt wound type, is combined with a suitable accumulator or storage battery and work circuit. v

It will, of course, be understood that the showing in the present case, is simplv intended as an illustration of one system, wherein the present invention may be employed to advantage, but it is not to be considered in any sense as a limitation of the invention.

In the diagrammatic view, the dynamoelectric-machine is designated by the 'nunicral 20, and has a shunt circuit, comprising the wires 9.2- and 9.3, connected with the brush 24 and one side of the field Winding 26, the opposite side of said field Winding being connected to the opposite brush'27, V by means of the wires 28 and'29.

This shunt circuit includes .certain of the elements of the regulator, Which are automatically controlled to vary the strength of 'the shuiit field excitation, and thus vary the voltage of the out-put of the generator.

In order to reduce the number of circuit Wires, and various connections, when comlbining the regulator 'with a system of the present type, there are providedicer'tain ground connections, which' greatly facilitate vfthe assembling of- Ethe system.

The regulator itself, embodi'es, broadly, a

movable element or plunger 40, ybuoyantly mounted -Within a suitablel casing or tube 41, andi partly submerged Within a body -of :conductive material 42,-the density o'f'whi'ch, and the Weight of 'the movable element,

"being so proportioned that the degree of normal submersion of the movable element,

lmay be accurately controlled.

Whilethe normal position-of the'movable element is controlled as `stated above, 'the ope'rationf thereof 'is controlled automatically, by means of a magnetic-condition set up, throughf'the 'medium of the coil A43, which, as will appear hereinafter, isconnected directly across the 'main circuit.

The relation of the voltage coil to the movable -or` -plunger element 40, is important, inasmuch as the movement of the plunger, in response Ato tthe effect of the magci'irrcn't:through ythe voltage coil, will be cont-rolled vinitially by thedistance to which the plunger normally extends into the in terior of the said coil. This, of course, may

4be accurately regulated by the position of the regulator tube or casing, relative to the voltage coil, inasmuch as the movable element hasa given normal position, Within said regulator tube.

A bracket element 44 is therefore provided, for supporting the voltage coil and also to adjustably support the container `tube, relative Ithereto.

The voltage coil 43 is preferably contained in a casing 45, which is made of magnetic material and is provided with a vcap or cover 32, having an opening registering with the opening through the center of 'the coil. In order 'that the coil and casing may be maintained in correct position and also to facilitate the assembling of ythe coil and its associated parts, the bracket element is provided with an upwardly extending tube 46, preferably of non-magnetic material, which fits snugly within :the opening formed in the center of the coil. By connecting this extension to the bracket, the assembling of the regulator tube, as well as, the voltage coil, is facilitated.

It will be seen from the above that the regulator tube 41 and the voltage coil 43, as well as its covering45, are 'independently vmaintained and supported by the bracket 44, so. that-theplunger 40, carried by the tube, maybe normally so positioned, relative. to the coil, that a predetermined voltage of current passing therethrough, Will be 'eife'otiveftoidrawlthe plunger element upward into the coil, out of the conductive material, a predetermined degree, ymuch in lthe same manner as the action of a solenoid.

'"(Df course, fit Will-be o'bvious fthat 4'by locat- 'Ing theplu'ngerA element -in various positions, relative to the* 'voltage coil, different voltages-may -be initially effective, to cause :the nvithdraiv'al ofthe plungerelement, a. sufficient 'degree to 1cut -in enough resistance to '-reluce'tlie field excitation, to secure diffe1'ent-1desi"1ed- A`conditionsof the out-'put ofthe generator.

'One manner `of securingthis -result will *be appa-rent by referring to Fig. 3, wherein 'it will be seen that the -loWer portion lof the @regulator tube is` threadedas at.47, -to cooperate'vviththe adjusting nut 48,*W'hich is `p'ermanen'tlybut rotatably held, relative rto the regulator, 'between the :projections 49 and'49, formed on the supporting bracket. By making this regulator tube adjustable, 1thro'mghthe operation of lthe nut 48, extremely l'line and accurate adjustments -of the-regulator casing and consequently, of

t the'movable plunger,'relati ve to 'the'voltage roll, may bemade from time 4to time, -to `either 'vary conditions, as desired, -orl to -readjust 'the regulator *to meet some newI requi rements.

Theregula'tor casing 41- is preferably of tubular constructionV and must be of suchmaterial 'that it will be impervious 4to 'the attack of any of the qualities of-'the conductive material, vwhich is preferably mercury orquick silver.

"Oneend of the tube or casing is inclosed :by means ofthe plug or insert 50, which has va 'guide 5"1project1'ng 'therefrom into Ethe interior ofthe regulator vcasing and substautially concentric thereto.

The plunger "element 40, is supported within the regulatorcasing, simply by the buoyancy 'thereof, relative to the body of conductive material. Because of this fact, that portion 'of the plunger which lies within the voltage coil should have a sufficient degree of permeability, so that the effectiveness of the magnetic circuit will, at a predetermined critical voltage passing through :the ooil, begin to Withdraw the plunger from the conductive material.

Now, as soon as ithe plunger is drawn into the coil, .the Astrength of the magnetic circuit is increased and this effect compensates for the apparent increase in the Weight of the plunger as it is withdrawn from the' conductive material. This apparent increase in the weight of the plun er is due to the decrease in the buoyant e ect as the plunger is withdrawn from its normal position.

The normal degree of submersion of the plunger is carefully proportioned by the weight thereof, relative to the density of the body of material in which it is floated.

As will be seen from an inspection of Fig. 4, the lower portion of the plunger is of tubular conformation, and carries on its outer surface, a high resistance winding 60, which is so applied that the space between the successive turns of the winding, varies. Thus, it will be seen that upon a given initial movement of the plunger, a certain number of turns of the resistance wire will be withdrawn from the conductive material, and cut into the circuit to be controlled, while for a further increment of movement, a different number of turns of resistance will be cut into or out of the controlled circuit.

One of the characteristics of an electric machine of the type shown in the present instance, is that as the speed increases, and the machine reaches a fairly high speed, a greater amount of resistance must be cut in for the increased speed than when the machine is operating at fairly low speeds. The present invention meets this condition by varying the distance between the successive turns of the resistance unit on the p l unger, so that at comparatively low speeds, a relatively small number of turns of resistance will be cut into the field of the generator for a given movement of the regulator plunger, while for an equa-l increment of movement of the plunger, after the machine lias rotated at comparatively high speeds, a greater number of turns of the resistance will be cut in, thus introducing a greater amount of resistance in the field circuit.

The lower end of the plunger element is provided with a disk 57, having a suitable Vbearing or opening 58, which is of such size as to permit the passage of the upwardly extending guide 51 therethrough.

A series of openings o1' perforations 59 are formed in the body of the disk 57, so that the conductive material within which a portion of the plunger element is submerged, may readily pass therethrough, into the interior of the plunger. This structure provides a damping efl'ect on the movement of the plunger, thus preventing any tendency of fluctuation or movement of the plunger element, other than that effected by the magnetic circuit.

One of the important features of the prescnt invention is to provide a regulator, wherein the movement of the plunger element, will, substantially, be the only element which will have eilect to cut in or out resistance, to vary any given electrical condition. That is, in the present invention, the displacement of the conductive material is made efective only to a slight degree, relative to the resistance, by the movement of the plunger element.

This result is secured by making the lower portion of the regulator plunger of tubular conformation, so that that portion which is normally submerged within the conductive material, consists of a relatively thin shell. As has heretofore been described, the shell portion of the plunger has series of turns of lhigh resistance winding 60, mentioned heretofore, so applied that the lower end thereof can be connected to the lower extremity of the plunger, in any suitable manner, as at 61, while the upper terminal thereof can be readily passed through an insulated opening 62, formed in the side of the plunger and secured to the downwardly projecting end of the conductive plug 63.

A thin layer of insulation 611, preferably mica, is interposed between the high resistance winding and the body of the plunger element, the function of which will appear as the description progresses.

The upper part of the plunger element, .which comprises the head portion 65, is provided with the reduced shank 66, which has a press fit within the insulating sleeve 67.

The head portion (S5 is hollow and is lined with insulation, as at 68, thus forming an insulated chamber 74. The upper end of this chamber has a disk G9, carrying the bearing 70, while the enlarged head of the plug 63, which, as has been described, is connected with the resistance winding G0, forms a bottom of conductive material for said chamber.

The bearing at the upper end of this chamber is of substantially the same construction as that provided at the lower end of the plunger, through which the guide element 51 passes. A needle or pin 72, similar to the element 51, is secured to the cover 7 3 of the regulator tube and projects downwardly through the bearing 70, into the chamber 74. These guiding elements are accurately alined and are adapted to prevent undue lateral movement of the plunger 40.

The function of the needle or pin 72 is not only to cooperate with the guide 51, to maintain the alinement of the plunger, throughout its movement, but also to form a part of the circuit to be controlled. This is arranged by inclosing a quantity of conductive material within the chamber 74, which will be of such volume that it will at all times be in contact with the pin 72.

Thus, the current passing through the main body of conductive material 42 must also pass through a short portion of the resistancc'winding which connects With= the pinGB, in orde-r to reach the conductive material contained in the chamber 74.

As will appear hereinafter, any variation inthe-Weight' of the plunger ele-ment may be compensated for byl the operationorA adjustment ofIl the rheostat' 55, butit will also be seen thatby varying the quantity of mcrcury placed Within the chamber 74, practically the same result' will be obtained,.that is, the varying of the Weight of the plunger.

This is an-extremely important feature, inasmuch as it permits the degree of! submersion of the plunger Within the main conductive body 42, to be accurately maintained.

However, the volume of mercury contained Within said'chamber, should,- atl least, be ofsuch-hcight that the conducting needle 72 may project through the bearing in the head of the plunger and-contact' therewith, without'ncccssarily being of-such an extended length as to prevent the plunger from being operated suiicientlyto cut in substantially all ofthe highresistance Winding.

That is, rthere must be sufficient space for the plunger to be withdrawn from the main body of conductive material to cut in practically all of the resistance Winding carried by the plunger, previous to the impingement of the conductive needle 72, on the plug B, which forms the bottom of the plunger chamber. As a matter of fact, the amount of resistance carried by the plunger clement may be so arranged that itis necessary'to cut'inonly a portion of the totalwinding, to meet normal conditions, While the remainder of the resistance would simply be brought into use to meet abnormal circumstances.

Among the above named elements of the regulator are certain of those which have been described heretofore, as being included within the shunt circuit of the generator, that is. it will be understood that the wire 29 is connected with the terminal 170, which has electrical connection with the regulator casing 41, in such a manner that the current Will-normally pass from the said terminal,

through the bracket-44 to the tube 41, thence through the main body of conductive material 42, into the body of conductive material carried by the plunger, via any of the resistance windings which may be uncovered, and plug G3, ncedle`72, through the terminal S() =into the wire 2S, and thence through the Iield'winding 2G, substantially short-circuiting the resistance G0, carried by the plunger clelnent.

Initially it will be seen that the field circuit will be substantially free from resistance, at least there Will only be a small amount cut inl Now, as the speed of the generator increases, the current value through the main circuit will tend to increase and therefore the voltage across the line Will-also increase.

The voltage coil 43 is connected directly across the-main circuit, the current passing directly from the Wire 29, through the terminal connection 170v'to the grounded connections 112 and 113, thence through the rheostat'handlel 151, and fif this is in position to cut outl theentire rheostat Winding 55, the currentwill flow directly through the winding 43, vWire 111, .to Wire 102, Which'is connected with theI brush 24 of the generator'. The Wire 29 is-of course connected With the brush=27, so that it will be seen that the coil'43-is-- directly across the generatorbrushes:

Under certain-conditions, tw'ill be necessary to move the rheostat 151E over'the resistance 55,-.in order'toincrease or decrease the voltage through the coil 43, so as to either increase or decrease the magnetic pull on the plunger 40.

Thistlow. of current'willtend to create a magnetic field, but itfwill be obvious in the present instance, that= this field must not be built up suiiciently to attract the plunger element to cut resista-nce into the shunt field, until after the cut-outurelay device 182 has been closed. Thiscut-out-relay 182 is adapted to pre-vent the bac-k flow of current from the storage battery to the generator, at such times as l'the generator is in-inoperative position, or to pre-vent suchfa-flow ofcurrent at such times as the battery voltage may be greater than-the voltage of the out-put of the generator;

This is-an important feature of the present invention, inasmuch as if the regulator IiS brought into operation, .to cut resistance into the shunt field, andthus maintain the shunt field ata voltagev below that which closes the cut-outv relay, it Will'be impossible to close the cut-out relay, which will, of course, prevent the proper charging of the battery. Therefore, it: is necessary that the cut-out relay be so proportioned as to its windings and mechanical construction, that it will close ata lower voltage than that necessary to bring the resistance into eifect, relative to the field.

The functions of the regulator, relative to the main circuit-and the accumulator, will be i better understood from the following description: Supposing that the generator is to be operated to charge the battery, which it will be supposedis in discharged condition. The initial action of the generator is to pass current'through the shunt circuit herctofore described, that is, from the brush 27, through Wire 29, terminal 170, through the mainbody of conductive material 42, contained in the re lator plug, the body of conductive material carried by the plunger, the conductive needle 72, into the Wire 28, through the shunt-field, back to the opposite brush-of the generator 24.

At the same time, a small amount of current is passing from the brush 27, through thewire 100, to the ine winding 101 of the relay 182, across to the opposite side 102 of the main circuit, back to the generator.

Now, as soon as the voltage of current passing through the fine winding of the cutout relay, increases suiciently to actuate the armature 104, to close the main circuit through the contacts 105 and 106, the current will begin fiowing through the wire 107, heavy Windlng 108, contacts 105 and 106, to one side of the battery 110, via the wire 109, through the battery and back to the generator, via the Wires 102 and 22, and the brush 24.

However, the voltage of the out-put of the generator should be controlled with relation to the normal voltage of the battery, so in the present instance, the voltage coil 43' of the regulator, is connected directly across the main circuit, by means of the wires 111 and 29, and ground connections 112 and 113; thus the coil will be subjected to the voltage of the generator, if that be the controlling voltage, or to the voltage of the battery, at such times as the battery is fully charged and its voltage tends to increase beyond normal.

To illustrate the above, suppose that the generator is to be employed to supply current to Work circuits, and suppose further, that the voltage of the Workcircuit or translating devices included therein, is six volts, the regulator must be so adjusted that when the voltage through the coil 43 increases above a predetermined maximum such as six volts, the regulator plunger will be withdrawn from the body of conductive material in which it is normally submerged, to cut in sufficient resistance into the shunt field to reduce the excitation thereof, and thus reduce the voltage of the out-put of the generator, to a certain predetermined point, as for instance, to six volts and to maintain the same at this point, regardless of increases which may occur in the gencrator speed.

However, if the battery is also included in the main circuit, and is cut in, as is shown in diagrammatic Fig. l, between the Igenerator and the work circuit, as soon as the buttery is fully charged, the back E. M. F. will tend to decrease the charging current so that injurious over-charge of the battery will he prevented.

,lt has been found that where a body of conductive material, such as mercury, is raised and lowered intermittently, to different degrees, there is a tendency for the material, if it is a liquid, to split up, so that small. particles thereof will tend to adhere to the interior of the vessel within which it is contained, and it has been found that especially in instruments of the type set forth herein, the splitting up of the material and the adherence thereof, to the sides of the regulator tube, or casing, may effect the efficiency and accuracy of the regulator.

There is also a tendency of the mercury,

when the regulator receives sudden shocks 'on a vehicle, it will be subjected to a practically continuous series of shocks and vibrations.

It has been found that the above objection may be practically eliminated by placing a suitable oil in the casing 41 over the body of conductive material, this imparting a damping effect on the body of conductive material and preventing injurious fluctuations thereof, due to vibrations or shocks.

This oil, which is designated by the numeral 150, will also lubricate the interior of the regulator casing and the plunger 40, so that the mercury will be prevented from adhering to the sides of the plunger and casing. e

It will, of course, be obvious that a portion of the body of oil will enter the chamber 74 and thus provide a simple damping and lubricating effect on the conductive material contained therein.

It has been found that care must be exercised in the selection and preparation of the damping and lubricating oil, inasmuch as it must be of such properties that it will not attack either the tube 41, the plunger element 10, or the body of conductive material, or in fact, any of the parts which may be brought into contact therewith.

In manufacturing the plunger element 40, in large quantities, it is practically impossible to secure uniform weight and dimensions thereof. It is, however, extremely advisable that the loss or excess in the weight of the plunger or in the dimensions thereof, be compensated for in some manner, so that some uniform and standard requirement, as to the amount of resistance to be cut in for a given voltage passing through the controlling coil 4-8, may be readily met, Without attempting to vary the quantity or density of the conductive material, and without necessitating further 'changes in the plunger element to bring the same to uniform Weight and dimensions.

In fFigs. 2 and 3, there is shown a small manually operated rheostat 55, the windings of which, providing the operating handle 151 is in one of its extreme positions, will be directly in series with the windings of the voltage coil 43. By adjusting this hand operated lever 151, any suitable amount of resistance may be cut into' the voltage coil circuit, which will result in either increasing or decreasing the strength of the magnetic field created by the current passing through the voltage winding 43.

In assembling the various parts of the present invention, it is only necessary that the body of conductive material 42 be of such volume that it will normally cover the turns of resistance winding carried on the exterior of the plunger. As soon as any movement of the plunger takes place, through the effect of the magnetic field, 4a certain number of turns of the Winding, in accordance with the degree of movement of the plunger, will be withdrawn from the conductive material and cut into the circuit to be controlled. As soon as the resistance' is cut into this circuit, which in the present instance is shown as being the field circuit, the excitation thereof, will be reduced, whereby the voltage of the generator output will also be reduced. Thus, by adjusting the rheostat to regulate the voltage of current necessary to create a magnetic field of sufficient strength to properly operate the plunger, variations in the weight or dimensions of the plunger, may be readily compensated for.

Inasmuch as instruments of the present type are employed to accurately indicate,

measure, or control very slight changes in' the volta-ges of a given circuit, some means must be provided to compensate for temperature effects upon the elements of the regulator and it follows that in case a storage battery is combined with the present system, it is also desirable to compensate for the varying temperatures thereof, to secure suitable and uniform results.

It is a well known fact that the internal resistances of a battery increase when the temperature lowers, while the resistance of the voltage coil 43, will tend to decrease as the temperature lowers. The reverse of this action, of course, takes place when the tempera-ture increases.. The rheostat 55, which has been referred to heretofore, is designed to compensate for temperature changes which take place, either in the battery or voltage coil, or in fact, any temperature changes which may effect the regulator. These functions of the rheostat are in addition to those heretofore set forth.

The structure of the rheostat set forth in the present instance, is clearly shown in Figs. 2 and 3, and comprises an insulating sleeve 155, having a flange 15G. The sleeve 155 carries a high resistance winding 157, which in turn has a core of insulating material 15S. One terminal 176 of the high resistance winding 157 extends through the insulating sleeve 155 and has electrical connection with a metallic sleeve 160, which is indirect contact with the regulator tube 11. As has been described heretofore, this tube has electrical connection with the terminal post 170, to which the yline wire 29 is connected.

This connection of the terminal 176 of the rheostat Winding with the sleeve 160, is indic'ated in Fig. 1, by means of the ground connections 113 and 112. The connection between the rheostat winding and the voltage coil 43, is secured byv means of the angular arm 172, which projects down through the supporting portion of the bracket 44, and has a frictie'nal connection or engagement with certain turns of the resistance winding.

'The entire rheostat heretofore described, is resiliently mounted intermediate the arms 180 and 181, and the voltage coil 43, by means of the spring 174` This spring arrangement always maintains some turn or turns of the winding in good contact with the arm 172, and at the same time, permits the movement of the sleeve 155, together vvzith the Winding 157, relative to the arm 1 2.

When the instrument lis initially assembled and is installed in the electrical system,

a predetermined standard of operation is required, that is, the plunger `elelnent must be so constructed and arranged relative to the voltage coil, and the voltage coil must be of such construction thatreurrent up to a predetermined voltage may be passed through the voltage coil, without creating a magnetic -field of sufiicient strength to raise the plunger element and .thus cut in resistance into the circuit te be controlled.

However, as soon as the voltage of this current rises beyond a predetermined point` a magnetic field of sufficient strength to operate the plunger element, must be created, and the plunger element must be in such position, relative to the voltage coil that the plunger element will be actuated immediately, as has been described heretofore.

Variations in certain of the elements of the system, due either to temperature effects or to slight lin-uniformity in the construction of the elements, may be compensated for by the operation of the sleeve 155, of the rheostat 55, so as to increase or decrease the critical voltage which will cause the initial operation of the plunger element.

In Fig. 7, there is illustrated a modified form of the plunger element, wherein the body of conductive material, carried in the chamber 741 of the plunger element embodied in Fig. 4, is eliminated.

In this form of the plunger, the structure is practically the same, with the exception that there is no necessity, as will appear hereinafter, for lining the chamber 74 with insulating material.

In the present instance, a head element 200, which comprises a ring, is mounted at the upper extremity of the plunger, in any suitable manne-r. The interior face of this ring or head element 200, is adapted to receive and carry two smaller rings 201 andl 202, which have their co-adjacentfaces oppositely beveled, as at 203, to provide the chamber 204.

These ring elements 201 and 202 are designed to form a line bearing for the guide element 72, and in orderi to reduce the amount of frictional resistance between the portions of the elements 201 and 202, with the needle 72, the outer faces of these ele ments are beveled as at 205. This result, that is, the reduction of frictional resistance between these elements, is further effected by constructing the elements 201 and 202 of substantially non-abrasive materiahwhich' however must be of good electrical conductivity.

It will be seen that the chamber 204 has a central opening, through which the needle 72 passes, and it is therefore neceary that the material contained Within said chamber, and which should comprise material of good conductivity, should have sufficient surface tension to prevent leakage of the same, when the plunger element 240 is moved from one position to another.

One material which has been found to answer the requirements for use under the above conditions, is mercury, but it is to be understood that the present invention is not to be limited to the use of mercury, but that any other material or mam having the required characteristics may be used instead.

However, in the present case, the chamber 74, Will simply provide a space to reecirc the needle 72, at such times as the plunger element 240 is moved upwardly. The remaining structure of this modification is substantially the same and further detail description Will therefore not be given.

Fig. 8 illustrates a. type of regulator which is slightly different from those embodied in Figs. 4 and 7, and comprises an outer casing 41. lVithin this casing, a plunger element 400 is positioned. and is buoyantly supported by thc body of conductive liquid 42. This plunger element, however, in this` modified form, is so arranged when in assembled position, that it may be readily removed from the tube 41, by first removing the inclosure 41. In order to accomplish this, the plunger 400 is connected to the anchor bolt or plug 416, which forms a part of the inclosure 41a; this anchor bolt or plug being electrically connected with the terminal post 403, which also forms a part of the inclosure or cover 41".

In the present modified forni of the invention. the manner of effecting the electrical connection between the bolt or plug 416 and the terminal post 403, is by means of a helix 401. This helix, however, has n0 supporting function, relative to the plunger element, it simply constituting a means for conducting the current from the plunger element tothe terminal post 408. The plunger element, itself, comprises the shell 405, having a solid head portion 406, separated from the shell 405, by means of the insulating sleeve 407.

This solid head portion is' connected to one end of the resistance Wire 60, and also to one end of the helix 401, as is clearly shown in Fig. 8.

In order to prevent objectionable lateral movement of the plunger element, a series of guiding elements 410, shown in the present illustration, as being of insulating material, are mounted at the opposite extremities of the plunger element and project outwardly into proximity With the interiorfof the casing 4l.

An insulated guard 412 projects downwardly from the cover 413, and 4protects the 'upper portion of the helix 401 from inadvertent contact with the regulator casing 41.

As a means for dis-assembling or removing the plunger element from its position within the casing 41, a small flexible connection 415 is connected to the terminal post 403, through the means of the anchor nut or bolt 416, and to the upper extremity of the plunger element, by means of a similar anchor nut 417. i

By having this flexible connection between the terminal post 403 and the plunger ele- 100 ment 40, of such length that there is normally no strain thereon, it will be seen that the only eect that this connection will have is to facilitate the removal of the plunger from the casing.

It will, of course, be understood that a certain amount of oil is provided in the present form, for the saine purposes described in connection with the forms shown in Figs. 4 and 7. The other details of construction are 110 similar to those set forth in the description of the above mentioned figures` ll'hile the form of mechanism herein shown and described constitutes a preferred forni of embodiment of the invention, it is 115 to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

lVhat I claim is as follows:

1. In the regulation of electrical systems, 120 the combination with a controlling circuit and a circuit to be controlled; of a .regulator comprising a casing having a body of conduciive material therein; a resistance device connected with the circuit to be controlled but 125 normally short-circuited by said conductive material; a moval'ile element buoyantly supported in said conductive material and operable through the effect of the controlling circuit to cut said resistance into and out of 130 the circuit tobe controlled; and a depending guide.eleanent secured to .said casing and adapted-to passginto achamber formed in the movableelement, to maintain-the mov- -able element .in alinement -throughout its degree of: movement Iand alsoto form a part of; the circuiti to be controlled.

2. In the' \regulation of electrical systems, the combination with a controlling circuit ,and acircuittobe controlled; of, a regulator comprising =a casing having a-body of conductive; material therein a; resistance device connected to the circuit to be controlled but .normally short-circuited bythe body ,iofvconductivefmaterial; a movable element buoyantly supported in said conductive material and. operable throughfthe effect of the controlling-circuit, to out said resistance device=into andout of the circuit to be con- 2o itrolled, said movable element being provided with chambers in the opposite endsthereof; and guides connected :.to opposite ends of said casing,.each of Said guides .adaptedto extend into one of the chambers formed in :.said g movable element, for r maintaining :the movable Aelement in alinement throughout its. degree of movement.

3. :In the regulation of electrical systems, the combination with a controlling circuit A. anda circuit to be controlled of a regulator comprising a casing having a body of conductiveliquid contained ytherein and forming a part of the circuit to be controlled; a

resistance unit normally sliort-circuited by the body of liquid contained in said casing, butoperable to be `Withdrawn from said liquid and cut into the circuit to be controlled; and a movable element adapted to carry said resistance device, said movable element being buoyantly supported by the conductive material contained in said casing, and a variable body of conductive material carried by the movable element and also constituting a part of the circuit to be controlled; and a guide element connected to said casing and adapted to project into the body of conductive liquid carried by the movable element, whereby to complete the circuit to be controlled.

4. In the regulation of electrical systems, the combination With a controlling circuit and a circuit to be controlled; of a regulator comprising a casinghaving a body of conductive liquid contained therein; a resistance device adapted to be cut into and out ofthe circuit to be controlled, but normally being short-circuited in the body of conductive liquid contained in said casing; a movable element carrying said resistance device contained in Said casing and buoyantly supported by said conductive liquid, said movable element being provided with a chamber in one end thereof; a variable body of conductive liquid carried in said chamber; and a conductive element included in the circuit to be controlled and adaptedfto depend into-saidchamlier and to be constantlyin contact with said conductive material, whereby thecircuitfto becontrolled is completed.

5. In 2a regulator-,the combination .With- .a casing, iabody of condnctivematerial contained therein; a movable element contained in .sa-id casing v and partly submerged in said conductiveimaterial; and .a bearing of.

tain the alinement of the movable -element,

throughout its degree of movement.

7. In a regulator, the combination with a casing, a body of conductive liquid vcontained therein; amovable element contained in said casing and partly submerged in-said liquid` -said element having chambers at-.its opposite ends; bearings of substantially nonabrasive material-positioned at the open ends of said chambers; and-guide elements -connected to said casing and extendingv through each of said lbearings to maintain the, alinement of the movable element, throughout its degree of movement` S. 4In a regulator, the combination with a casing, and a body of conductive liquid contained therein; of' a movable resistance carrying element contained in said casing and partly submerged in said liquid, said plunger element having a. chamber open at one end; an insulated lining for said chamber; a body of conductive material carried in said chamber and electrically connected with the resista-nce carried by the movable element; and a conductive element constantly in contact with said conductive material 9. In a regulator,4 the combination with a controlling coil and a regulator tube; of a bracket element independently supporting said controlling coil and tube, said tube having a threaded lower end and a nut construction maintained in a determined position by said bracket, cooperating therewith, whereby the regulator tube may be adjusted relative to the controlling coil.

10. In apparatus of the character described, the combination with a receptacle, of a liquid electrical conductor contained therein, a tubular resistor mounted toreciprocate in the receptacle in engagement with the liquid .electrical conductor .contained therein and having its llower end provided with a permanently uncovered restricted outlet opening of a substantially smaller diameter than the bore of the tubular resistor whereby the liquid electrical conductor may enter the interior of the tubular resistor and gradually discharge therefrom upon the upward movement of the tubular resistor, and electrically operated means to raise the tubular resistor.

11. In apparatus of the character described, a receptacle, a liquid electrical conductor contained therein, a substantially vertically movable tubular resistor disposed Within the receptacle and provided near one end with an opening, and means to move the tubular resistor.

12. In apparatus of the character described, the combination with a receptacle, of a liquid electrical conductor contained therein, a tubular resistor having its lower end provided with a restricted outlet opening whereby the liquid electrical conductor contained therein will be gradually discharged from the interior thereof upon the upward movement of the tubular resistor, and means to raise and lower the tubular resistor.

In testimony whereof I aiix my signature in the presence of two subscribing Witnesses.

CHARLES F. KETTERING.

Witnesses:

JOSEPH W. McDoNALD, WALTER N. Rmnni..

Copies of this patent may be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C. 

